Abstract: A diaphragm valve for the water intake in irrigation systems or similar comprises a hollow body having a port to connect a hydraulic or pneumatic system to the interior of the body of the valve and at least one ventilation opening through a side wall or walls of the body from the exterior to the interior of the valve. A diaphragm is movably mounted within the interior of the body and normally closes the port. There is a bleed aperture through the diaphragm around the guide member to a cavity behind the diaphragm. When the pressure on the port side of the diaphragm falls below the external pressure, the diaphragm will move away from the port to open the port to fluid entering the interior of the body of the valve through the side wall(s) of the body of the valve, and the diaphragm will move to close the port when the pressure on the port side of the diaphragm is equalized with the external pressure.

Abstract: A pipe coupling comprises a body part having a hollow interior and a rotatable sleeve captively mounted to the body part of the coupling such that the end of a length of pipe connected to the coupling passes through the rotatable sleeve to the hollow interior of the coupling. The rotatable sleeve has a tapered interior of narrowing diameter towards the pipe entry end of the rotatable sleeve. A circular band is coaxially positioned inside the rotatable sleeve. In use a pipe end is pushed into the threaded sleeve to the hollow interior of the coupling, and through the circular band. Force on the pipe away from the coupling further closes the circular band about the pipe end. Preferably the circular band has a threaded interior.

Abstract: A slide control system suitable for a graphic equaliser comprises a number of slide controls grouped into sets of at least two and typically three slide controls. Bridge means including a knob or gripping portion is mounted in one of the slide controls and extends across to releasably engage the adjacent slide control(s) so that all the slide controls of the set normally are coupled for movement together in a single operation, but temporary release of the bridge means from the adjacent slide control(s) enables separate movement of each of the slide controls of the set relative to one another.

Abstract: A pipe coupling has a body having a hollow interior including a tubular tail onto which the end of a pipe can be engaged. A coupling nut is captively mounted about the body of the coupling and has a screw threaded interior. When the end of a pipe has been pushed sufficiently onto the tubular tail, rotation of the coupling nut will threadedly engage the nut onto the exterior of the pipe end and draw the pipe further onto the tubular tail of the coupling. The tubular tail of the coupling may be formed as a separate replacable component from the balance of the body of the coupling such that the tail can be removed and substituted by a replacement tail of larger or smaller outside diameter to accomodate larger or smaller pipes.

Abstract: A diaphragm multi-port valve assembly particularly for controlling cylinder and piston assemblies. The valve assembly has communicating chambers which are normally separated by a diaphragm, the chambers being connected by a bleed so that the pressures in the two chambers can equalize. Each chamber is connected to or separated from an appropriate port or other chamber by a pilot valve.